Detection of hepatitis B virus DNA in human serum based on highly sensitive electrochemical sensor

The determination of specific DNA sequences in biological samples such as serum, organs, and body fluids is of great importance in biomedicine. Synthetic single-stranded DNA fragments of the Hepatitis B virus were immobilized as specific probes on the surface of gold electrodes using a self-assembled single-molecule membrane method. The electrode combined with the electroactive Hoechest 33258 constitutes the DNA electrochemical sensor. The film-forming conditions of self-assembled single-molecule membranes were explored during the immobilization of Hepatitis B specific DNA probes. The results showed that a probe concentration of 100 mu g/mL and an immobilization time of 12 h was more favorable for the immobilization of the probe. We also explored the DNA immobilization and hybridization mechanism. We used a DNA electrochemical sensor for the qualitative and quantitative detection of standard concentrations of complementary DNA in solution. The results showed that the linear detection range could reach 0.05 similar to 1 mu g/mL, and the limit of detection could reach 10 ng/mL when using the electrochemical sensor to detect standard DNA samples. On this basis, we have also successfully used DNA sensors for Hepatitis B virus detection serum.